/*java jdk 1.7+
# -*- coding: utf-8 -
'''
Created on 2020年05月10日
@author: zxyong 13738196011
'''*/

package com.utils;

import java.security.MessageDigest;

public class MD5Util
{
	private static String byteArrayToHexString(byte b[])
	{
		StringBuffer resultSb = new StringBuffer();
		for(int i = 0;i < b.length;i++)
			resultSb.append(byteToHexString(b[i]));
		return resultSb.toString();
	}

	private static String byteToHexString(byte b)
	{
		int n = b;
		if(n < 0)
			n += 256;
		int d1 = n / 16;
		int d2 = n % 16;
		return hexDigits[d1] + hexDigits[d2];
	}

	public final static String getMessageDigest(byte[] buffer)
	{
		char hexDigits[] =
		{ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd',
				'e', 'f' };
		try
		{
			MessageDigest mdTemp = MessageDigest.getInstance("MD5");
			mdTemp.update(buffer);
			byte[] md = mdTemp.digest();
			int j = md.length;
			char str[] = new char[j * 2];
			int k = 0;
			for(int i = 0;i < j;i++)
			{
				byte byte0 = md[i];
				str[k++] = hexDigits[byte0 >>> 4 & 0xf];
				str[k++] = hexDigits[byte0 & 0xf];
			}
			return new String(str);
		}
		catch(Exception e)
		{
			return null;
		}
	}

	public static String MD5Encode(String origin, String charsetname)
	{
		String resultString = null;
		try
		{
			resultString = new String(origin);
			MessageDigest md = MessageDigest.getInstance("MD5");
			if(java.util.Objects.equals(charsetname,null) || "".equals(charsetname))
				resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
			else
				resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));
		}
		catch(Exception exception)
		{
		}
		return resultString;
	}

	private static final String hexDigits[] =
	{ "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e",
			"f" };
}